CSS Popup Login Box

Avg Bid (USD)
Project Budget (USD)
$30 - $250

Project Description:
I need a popup window that looks like the one in the link below but also has 1 (one) form field to:

I need to be able to trigger this code by either pressing a button or on page load. the idea is that it either (a) prevent the website from loading until a valid input is received or (b) it masks the current page from the user.

Skills required:
CSS, Graphic Design, HTML, PHP, Website Design
About the employer:
Public Clarification Board
Bids are hidden by the project creator. Log in as the employer to view bids or to bid on this project.
You will not be able to bid on this project if you are not qualified in one of the job categories. To see your qualifications click here.

$ 83
in 2 days
$ 100
in 1 days
$ 44
in 2 days
$ 83
in 1 days
$ 54
in 1 days
$ 102
in 5 days
$ 103
in 3 days
$ 131
in 2 days
$ 55
in 0 days
$ 103
in 7 days